Studies on intramolecular cycloaddition reactions of some isoquinolinium salts

Abstract

Thermally-induced Intramolecular addition reactions of isoquinolinium derivatives bearing an alkenyl side-chain have been studied. Cycloadditions can occur across the isolated olefinic bond and the 1,4-positions of the isoquinolinium system to produce tetracyclic adducts. The chemistry of these adducts is compared with that of cyclo-adducts produced in intermolecular additions. Preparation of some of the isoquinoline derivatives involved alkylation of the parent base; 3-methylisoquinoline can be substituted either at the methyl group, upon reaction with aromatic nitrites or at C-4, using alkyl halides.